Progesterone Primed Ovarian Stimulation (PPOS) vs. clomiphene Primed Ovarian Stimulation (CPOS) in high responder (HR) patients undergoing controlled ovarian stimulation. A Randomised Control trial.

Objective: To compare the efficacy and safety of PPOS and CPOS in high-responder patients undergoing COS for IVF.

Methods: This one-year prospective, randomized, controlled trial included 86 high-responder patients. They were divided into PPOS (n=44) and CPOS (n=42). Both groups underwent COS with hormonal injections, and various parameters, such as LH surge, cycle cancellation rates, birth rates, implantation rates, and more, were measured and compared.

Results: The study revealed that LH surge occurred in 2.3% of the PPOS group and 2.5% of the CPOS group, with no significant difference (p=0.9). The cycle cancellation rates were 9.1% for PPOS and 10% for CPOS. Birth rates were 57% for PPOS and 54% for CPOS. Implantation rates were 45% for PPOS and 49% for CPOS. There was no significant difference in the duration of stimulation (PPOS: 11.30±1.96 days, CPOS: 11.41±2.02 days, p=0.807) or the total FSH used (PPOS: 2888.95±791.80IU, CPOS: 2808±834.52IU, p=0.655). The PPOS group had a mean of 19.58±8.07 retrieved oocytes, while the CPOS group had a mean of 21.87±10.02, showing no significant difference (p=0.807). Similarly, there was no significant difference (p=0.376) in the number of mature (MII) oocytes between the PPOS group (15.67±6.23) and the CPOS group (17.08±7.96). Post-trigger LH levels were significantly lower in the PPOS group (PPOS: 49.68±27.54IU/L, CPOS: 71.83±43.43IU/L, p-value 0.007), indicating LH surge suppression. Neither group reported cases of ovarian hyperstimulation syndrome (OHSS).

Conclusions: PPOS and CPOS offer similar outcomes in high-responder individuals undergoing COS for IVF, except for lower post-trigger LH levels in the PPOS group. Importantly, neither group experienced ovarian hyperstimulation syndrome (OHSS).